Material producers Avantor, Momentive, Elkem, DowDuPont and Shin-Etsu are developing more high-clarity liquid silicone rubber products.
Target markets for the ultra clear materials include health care, as well as automotive, indoor and outdoor lighting.
Public launch pending for Avantor
Beginning in mid-2016, Avantor Performance Materials LLC began introducing a new NuSil-brand high-clarity LSR product line to target markets and customers.
The new translucent LSRs are suitable for precision parts such as molded rubber stoppers, gaskets, seals, valves and O-rings and differ from the NuSil six-product medical-grade 5800 series in terms of clarity and operating temperature.
Development of the high-clarity line occurred over about four years, according to John Freedman, Avantor business unit director for biomaterials. An official public launch is pending.
Avantor produces the high-clarity LSRs at its NuSil silicone manufacturing facility in Carpenteria, Calif.
In addition to high clarity, the line allows for a broader operating temperature when compared to traditional LSRs, Freedman said.
Customers validating Momentive materials
Momentive Performance Materials Inc. of Waterford, N.Y., has several projects currently undergoing validation with selected customers, said Timothy Higgins, Momentive regional marketing manager for elastomers.
“We anticipate the products will be available commercially in the near future,” he said. Momentive offers 10 commercial grades of high-clarity LSRs globally.
Momentive has a broad LSR portfolio. The hardness range covers ultrasoft material in Silopren LSR 7005 with a 5 Shore A hardness for optical coupling pads up through ultra clear Silopren LSR 7090 with 90 Shore A hardness for lenses and illumination optics.
A recent Momentive high-clarity addition — Silopren LSR 7180 — is suitable for the street and area lighting market.
Elkem targets health care
Elkem Silicones, branded prior to Sept. 20 as Bluestar Silicones, offers new high-clarity LSRs for health care, implantables and general purposes, said Karen O’Keefe, business director for elastomers and marketing director for health care with Elkem Silicones USA Corp.
Elkem AS of Oslo, Norway, acquired Bluestar Silicones International of Lyon, France, and its upstream sister entity in Xinghuo, China, in June 2015 and has fully integrated the operations into its global Elkem Silicones division now employing 3,000.
Lighting a focus for DowDuPont
The performance silicones unit of Midland, Mich. and Wilmington, Del.-based DowDuPont Inc. pursues additional high-clarity optical-grade LSR solutions.
“We continue to build on the success of our moldable silicones portfolio,” said Rogier Reinders, global marketing director for lighting with the silicones unit. Reinders is based at DowDuPont’s European headquarters in Horgen, Switzerland.
In early 2017, the performance silicones unit, formerly Dow Corning, introduced three moldable optical silicone products: MS-4002 for complex and finely detailed optical parts and secondary lenses; MS-4022 for next-generation lighting applications; and MS-4007 providing additional options in molding and optical properties.
“The three new products in this family offer plastic-like, smooth optics that can be rapidly and readily prepared by injection molding,” he said. Optically, the products combine high transmittance with low attenuation and can enhance the lumen efficiency of LED lamps and luminaires. Relatively long light paths and wide light spectrum allow use of ultraviolet-C optics for special applications in addition to automotive and general lighting uses.
Shin-Etsu gaining visibility
Shin-Etsu Silicones of America Inc. is gaining visibility with its KE-2062 series of its optically clear liquid injection molded products providing heat resistance up to 392°F and hardnesses ranging from Shore A 30 to 70. The temperature tolerance is higher than comparable thermoplastics.
“We believe the American market is still growing modestly as the industry learns more about the value proposition of silicone and adopts this material in outdoor and general lighting applications,” said Eric Bishop, North American marketing manager at Shin-Etsu Silicones in Akron, Ohio.